Built-up roof



' Jilly 9, 1935. H. c. MACAN 2,007,403

BUILT UP ROOF Filed March 17, '1954 INVENTOR @1 Zach M/fim Zmf ATTORNEY 5' Patented July 9, 1935 PATENT OFFICE 2,007,403 BUILT-UP ROOF Harry G. Macan, Rutherford, N. J., assignor to Anaconda Copper Mining CompanmNew York, N. Y., a corporation of Montana Application March 17,

3 Claims.

tervening films of adhesive, and more particularly, the invention is concerned with a novel roof of the type referred to which includes both fibrous material and metal. The component parts of the new roof preferably take the formof strips which are placed so as to lie in overlapping relationand the manner in which the new roof is constructed insures that the parts thereof will be well bonded by the adhesive and the metal will be held firmly in place and not subject to being lifted and freed from the surface by the wind.

The roof of the invention maybe made in different ways, depending upon special local conditions, but in all forms, the roof includes one or more layers of fibrous material, over which are laid multi-part strips with adjacent strips overlapping. Each such strip includes fibrous material and metal and the strips are so laid that'the metal parts thereof are wholly concealed and protected by fibrous material in the completed roof. As the strips are laid, adhesive material, such as asphalt, is applied to the entire under surface of each part of each strip and the parts of the strips are so arranged in the roof that there is no place where metal is bonded to metal by adhesive. The new roof affords numerous advantages over prior roofs in that it is more durable than roofs made entirely of fibrous material and it is cheaper and of longer life than composite roofs containing both fibrous material and metal, as heretofore produced.

For a better understanding of the invention, reference may be had to the accompanying drawing-in which the single feature is a view in per spective of oneform of the new roof illustrating the manner in which it is built.

Referring now to the drawing, the roof is shown as applied to-a roof structure II) which ordinarily consists of r bofing boards laid side by side on a suitable supporting structure. on these boards is placed fibrous material, such as roofing felt, and the felt is used in roll form and the strips II of felt are placed in overlapping relation. Preferably, the strips are laid with headlap so that each strip overlies more than half of the next adjacent strip and also overlies the second adjacent strip by a less amount.

In the roof illustrated, the strips are laid with headlap and the strip I I thus overlies more than one-half of the strip I2 and also overlies the strip l3. In practice, the strips of felt may conveniently have a width of thirty-two inches and 1934, Serial No. 716,116

are so laid that a portion having a width of fifteen inches is exposed. With strips of that width laid in themannerdescribed, the strip II overlies a portion of the strip I2, which portion is seventeen inches in width, and overlies strip I3 to the extent of two inches. In some instances thirty-six inch strips are employed, in which event, the strip II overlies a portion of the strip l2 which is nineteen inches in width and overlies a portion of the strip I3 which is two inches in width. The lIl amount of overlap and headlap referred to may, of course, be varied as desired but ordinarily a two inch headlap is suitable and the lap will vary in accordance with the headlap and the width of the strips used.

In applying the various strips to the roofing boards, the roofer customarily places an edging strip I4 along the roof boards at the cave, a strip of copper frequently being used for the purpose. This strip is nailed to the roof boards along its 20 upper edge as at I5 and its lower edge is ordinarily turned over the ends of the boards as at I6 and held in place by nails I'II. Over the strip I6 is then laid a strip of felt I8 of half width and this strip is secured in place by nails I9 along its 25 upper edge. A full width strip 20 of felt is then placed over the strip I8 and secured in place by nails 2 I, the strips I8 and 20 being laid with their lower edges in registry and flush with the ends of the roof boards, The other full width strips 30 of felt, such as II, I2, and I3, are then laid, each strip being nailed in place along its upper edge. After the strips are thus secured in position, they are turned back and the surfaces beneath them are mopped with an adhesive, such as hot asphalt, 35 and the strips at once turned back fiat and pressed in position.v The arrangement of the strips described results in the entire roof surface being covered by at least two thicknesses of felt. I

Over the felt covering so provided are laid mul- 4Q tipart strips 22, each of which consists of a part 23 of metal and a part 24 of fibrous material, such as roofing felt. Various metals may be employed for the purpose such as copper, lead, zinc, etc., but thin sheet copper is preferred. Also, the metal 45 part of each multi-part strip is preferably of narrower width than the fibrous part and the two Darts are so laid that the metal is wholly concealed in the finished roof. In applying a multi-part strip, the adhesive 5 used, such as asphalt, is applied as at 25a to the surface of the fibrous covering and the metallic strip is then spread out and pressed in position upon the asphalt film. A film of asphalt 25b is then applied over-the metal and the fibrous part 55 I of the strip is then spread out over the asphalt. Nails 26 are driven through the fibrous and metallic parts of the strip along its upper edge to complete the laying of the strip. The first multipart strip laid along the eaves is so placed that the fibrous part thereof projects downward beyond the edge of the metallic strip with the projecting edge 21 of the fibrous part lying flush with the edge of the roof. The other edge of the fibrous part may then lie flush with the corresponding edge of the metal part of the strip or project slightly beyond it, but for best results the metal part of each multi-part strip should be wholly concealed.

In practice, the fibrous part of each multi-part strip may be a felt strip thirty-two inches wide and the metal strip used therewith may be thirty inches in width. These strips may then be laid with their edges which are to be overlapped lying in registry and the felt projecting two inches beyond the other edge of the metal. Each multipart strip is laid so as to overlie the strip previously applied, and preferably the metal part of the overlying strip overlaps the registering edges of the underlying strip by two inches. In some cases, it may be desirable to make the multi-part strips of a metallic part thirty inches in width and a felt part thirty-six inches in width. In this case, the lap of the metal part over the underlying strip remains at two inches while the felt part overlaps the underlying strip by eight inches.

In order to obtain all the advantages of the new construction, it is important that the metal part of each multi-part strip should have no portion exposed to the weather in the completed roof and the two parts of each strip should, accordingly, be laid so that the felt along its exposed edge projects beyond the metal. For convenience in laying the parts of the strips to obtain this relation, the metal part is made narrower than the felt and the strips are laid with one edge in registry. That is the best arrangement because there is then no place in the roof where metal is bonded to metal by the adhesive. However, some of the advantages of the new roof may be obtained, regardless of the relative widths of the felt and the metal parts of a multi-part strip, if those parts are laid in such manner that there is no metal exposed in the completed roof.

' In ordinary composite roofs made of metal and felt, it is the practice to lay the felt in the customary overlapping manner and cover it with metal strips also laid in overlapping relation. With that arrangement, the metal is usually bonded to metal and such a bond is'not as good as that of metal to felt. Because of the weakness in a metal-to-metal bond, there-is a tendency for the edges to become loose in time if the metal surface is not properly protected. Because of the high tensile strength of the metal, it offers resistance to the wind and when the bond is weakened or destroyed the metal will, in the course of time, be lifted by the windand freed from the roof. A coating of asphalt on the surface of the metal will delay this action to some extent but the use of felt over the metal, as in the present roof, provides the best protection for the metal. The felt itself has little or no tensile strength and even if the edge of the felt becomes loose, it is not likely to be lifted by the wind to any extent. It thus remains in position and serves to keep the metal from being lifted. In some roofs as now made, two plies of metal over the felt are provided but, here again, there is a metal-to-metal bond which results in the difliculties above mentioned.

If the new roof includes a layer of rag felt overlying the metal, the felt may deteriorate in the course of time, so that moisture may penetrate it and reach the metal beneath it. But the complete coverage of the roof with metal and the absence of any metal-to-metal bond prevent the water from reaching the underlying layers of felt which lie directly on the roof boards. Thus, even though the exposed layer of felt may deteriorate, the deterioration cannot progress down to the roof boards but is stopped by the complete metal layer and moisture cannot enter the building through the roof. When asbestos felt is used as the felt layer in the new roof, deterioration of the felt is indefinitely delayed, and the felt functions both to hold down the edges of the metal strips and to shed water.

With the construction described, the metal is wholly concealed by a layer of felt and the felt not only serves the purpose of keeping the metal in position but also protects the asphalt bonding the metal to the underlying felt from exposure to the sun along the edge of the metal. As is well known, asphalt deteriorates when exposed to the sunlight, and loses its ability to perform any bonding function. With the asphalt protected by the felt from the sunlight, it continues to act as a good bond for indefinite periods.

The new roof is consequently much more durable than composite roofs of felt and metal in which metal forms the exposed surface and the desired protection is obtained with what amounts to a single ply of metal over the entire roof surface. The newroof, therefore, provides the desired protection at low cost both for materials and labor.

What I claim is:

1. A built-up roof which comprises a roof structure, a layer of cushioning material lying substantially flat on and secured to the surface of the roof structure, and a plurality of multipart strips lying substantially flat on and secured by an adhesive to the cushioning layer and forming the outer surface of the roof, adjacent strips overlapping along their lateral edges, each strip consisting of an overlying fibrous element and an underlying flexible metallic element of such thinness and weight that an unsecured exposed edge of it on a roof would be lifted out of place by the wind, said fibrous and metallic elements being secured together face toface by an adhesive, the metallic element of each strip being afiixed by an adhesive in part to the cushioning layer and in part to a portion of the adjacent overlapped strip, the fibrous element of each strip overlying the metallic element thereof and extending beyond the overlapping edge of the latter and affixed by an adhesive to the fibrous element of the adjacent overlapped strip.

2-. A built-up roof which comprises a roof structure, a layer of cushioning material lying substantially flat on and secured to the surface of the roof structure, and a plurality of multipart strips lying substantially flat on and secured by an adhesive to the cushioning layer and forming the outer surface on the "roof, adjacent strips overlapping along their lateral edges, each strip consisting of an overlying fibrous element and an underlying flexible metallic element of such thinness and weight that an unsecured exposed edge of it on a roof would be lifted out of place by the wind, said fibrous and metallic elements being secured together face to face by an adhesive,

the metallic element of each strip being amxed in part to the cushioning layer and in part to the fibrous element of the adjacent overlapped strip, the fibrous element of each strip overlying the metallic element thereof and extending beyond the overlapping edge of the latter and. affixed by an adhesive to the fibrous element of the adjacent overlapped strip.

3. A built-up roof which comprises a roof structure, a layer of cushioning material thereon, said cushioning layer being composed of a plurality of courses of partially overlapped sheets of roofing material, and a multi-part outer covering on said cushioning layer, said outer covering comprising a series of overlapping courses each having an underlying relatively thin metallic element and an overlying fibrous element, the courses of said cushioning layer being adhesively secured together, and each course of said multi-part covering being secured to the cushioning layer and to its underlying course by a layer of waterproof adhesive, the overlying fibrous element of each course projecting beyond 10 the underlying metallic element and being adhesively secured to its underlying course.

HARRY C. MACAN. 

